The subject of this patent application relates generally to biosignal analysis, and more particularly to a system and associated methods for adaptive noise quantification in dynamic biosignal analysis.
Applicant(s) hereby incorporate herein by reference any and all patents and published patent applications cited or referred to in this application.
By way of background, biosignal sensors are commonly used to acquire biological signals which are used extensively in the assessment of various clinical physiological conditions—for example, without limitation, in the monitoring of a cardiac condition. Sensors are traditionally placed in contact with the skin of an individual, such as photodiode sensors (i.e., photopletismography) or voltage sensors (i.e., electrocardiography), and the physiological signals which result are examined. Some other sensors, such as magnetic sensors (i.e., magnetoencephalography) do not need to be in direct contact with the skin but rather merely in sufficient proximity to the skin. Such data may be used to monitor and/or evaluate the health and/or physical state of the wearer of such sensors.
While using such a sensor can provide an accurate measurement of a signal, there are several factors that can affect the signal quality, including, without limitation, stability, noise and/or sensibility. These limitations are due, at least in part, to factors related to relative movements between the biosignal sensor and the user which result in motion artifacts that corrupt the biosignal. This can be exacerbated when a sensor is included in a wearable device. In such a situation, the sensor needs to be integrated in a wearable—such as a garment, for example—in a minimally invasive manner that allows, for example, without limitation, flexibility and comfort to an individual's body; especially in movement. At the same time, the sensor must also be capable of measuring a signal accurately. Thus, motion artifacts are an inherent problem of biosignal sensing in the context of wearable devices and it is necessary to dispose of the proper tools to analyze the biosignal in this adverse situation. Thus, being able to estimate the signal-to-noise ratio of a biosignal is greatly important since making analysis decisions on noisy signals can lead to interpretative mistakes.
Aspects of the present invention fulfill these needs and provide further related advantages as described in the following summary.